1. Field
The present disclosure relates to a light emitting diode (LED) structure, and more particularly to a LED structure with a smooth surface for a reflective electrode.
2. Background
Light emitting diodes (LEDs) have been developed for many years and have been widely used in various light applications. As LEDs are light-weight, consume less energy, and have a good electrical power to light conversion efficiency, in some application areas, there have been intentions to replace conventional light sources, such as incandescent lamps and fluorescent light sources, with LEDs. Such LEDs produce light in a relatively narrow angular spread direction without side light so that the light cannot be easily collected by optical elements in a package. In other words, thin-film AlInGaN LEDs produce more light per steradian and photons generated therefrom can be efficiently utilized compared to the conventional lateral LEDs with sapphire substrate attached. However, the efficiency (Lumen/W) of the current LEDs is still not high enough to replace the conventional light source for general illumination or other light applications.
Therefore, there is a need in the art to improve the structure of the LEDs so that they emit light in more efficient ways than conventional LEDs.